欧美黑人3p-欧美黑大硬粗免费视频-欧美黑大粗-欧美黑粗特黄午夜大片-欧美黑白配性xxxxx-欧美黑b

Disc brake History

 

Early experiments

Development of disc brakes began in England in the 1890s.

The first caliper-type automobile disc brake was patented by Frederick William Lanchester in his Birmingham factory in 1902 and used successfully on Lanchester cars. However, the limited choice of metals in this period meant that he had to use copper as the braking medium acting on the disc. The poor state of the roads at this time, no more than dusty, rough tracks, meant the copper wore quickly making the system impractical.

The American Crosley Hot Shot is often given credit for the first production disc brakes. For six months in 1950, Crosley built a car with these brakes, then returned to drum brakes. Lack of sufficient research caused reliability problems, such as sticking and corrosion, especially in regions using salt on winter roads. Drum brake conversions for Hot Shots were quite popular. The Crosley disc was a Goodyear development, a caliper type with ventilated disc, originally designed for aircraft applications.

Chrysler developed a unique braking system, offered from 1949 to 1953. Instead of the disc with caliper squeezing on it, this system used twin expanding discs that rubbed against the inner surface of a cast-iron brake drum, which doubled as the brake housing. The discs spread apart to create friction against the inner drum surface through the action of standard wheel cylinders. Because of the expense, the brakes were only standard on the Chrysler Crown and the Town and Country Newport in 1950. They were optional, however, on other Chryslers, priced around $400, at a time when an entire Crosley Hot Shot retailed for $935. This four-wheel disc brake system was built by Auto Specialties Manufacturing Company (Ausco) of St. Joseph, Michigan, under patents of inventor H.L. Lambert, and was first tested on a 1939 Plymouth. Chrysler discs were "self energizing," in that some of the braking energy itself contributed to the braking effort. This was accomplished by small balls set into oval holes leading to the brake surface.When the disc made initial contact with the friction surface, the balls would be forced up the holes forcing the discs further apart and augmenting the braking energy. This made for lighter braking pressure than with calipers, avoided brake fade, promoted cooler running, and provided one-third more friction surface than standard Chrysler twelve-inch drums. Today's owners consider the Ausco-Lambert very reliable and powerful, but admit its grabbiness and sensitivity.

Racing breakthrough

Reliable caliper-type disc brakes first appeared in 1953 on the Jaguar C-Type racing car. These brakes helped the company to win the 1953 24 Hours of Le Mans,developed in the UK by Dunlop. That same year, the aluminum bodied Austin-Healey 100S, of which 50 were made, was the first car sold to the public to have disc brakes, fitted to all 4 wheels.

Mass production

The first mass production use of the modern disc brake was in 1955, on the Citroën DS, which featured caliper-type front disc brakes among its many innovations. These discs were mounted inboard near the transmission, and were powered by the vehicle's central hydraulic system. This model went on to sell 1.5 million units over 20 years with the same brake setup.

The Jensen 541, with four-wheel disc brakes, followed in 1956.

Disc brakes were most popular on sports cars when they were first introduced, since these vehicles are more demanding about brake performance. Discs have now become the more common form in most passenger vehicles, although many (particularly light weight vehicles) use drum brakes on the rear wheels to keep costs and weight down as well as to simplify the provisions for a parking brake. As the front brakes perform most of the braking effort, this can be a reasonable compromise.

Many early implementations for automobiles located the brakes on the inboard side of the driveshaft, near the differential, while most brakes today are located inside the wheels. An inboard location reduces the unsprung weight and eliminates a source of heat transfer to the tires.

Historically, brake discs were manufactured throughout the world with a strong concentration in Europe and America. Between 1989 and 2005, manufacturing of brake discs migrated predominantly to China.

2016-09-27 23:56:04
主站蜘蛛池模板: 日韩欧美无线在码 | 黄色美女网站视频 | 最近中文字幕免费版在线3 最近中文字幕免费在线看 最近中文字幕视频国语中文字幕 | 日本在线观看免费 | 97天天干| 国产精品成人观看视频免费 | 久久午夜鲁丝片午夜精品 | 亚洲国产综合人成综合网站00 | 一二三四在线观看视频 | 午夜成人免费影院 | 深夜福利免费在线观看 | 免费观看成人www精品视频在线 | 在线国产91 | 日韩欧美一区在线观看 | 朝鲜美女免费一级毛片 | 欧美日韩视频在线观看高清免费网站 | 99久久一香蕉国产线看观看 | 丁香五月天综合缴情网 | 黄网免费看 | 日韩欧美成人免费中文字幕 | 特级深夜a级毛片免费观看 特级淫片黑美女高清视频 特级做人爱c欧美网站 | 日本一级一片免在线观看 | 国产福利小视频在线播放观看 | 亚洲高清美女一区二区三区 | 亚洲国产成人久久综合一 | 福利视频第一区 | 亚洲一区二区三区在线网站 | 久热精品在线观看 | 日本一级网站 | 日本aaaa| 全免费毛片在线播放 | 日韩一区二区在线播放 | 男女视频免费网站 | 在线免费午夜视频 | 手机看片1024国产基地 | 国产成人精品久久一区二区小说 | 国产中文 | 日本一区二区三区在线 视频 | 日韩一区二区视频在线观看 | 狠狠大日本亚洲香蕉亚洲 | 久久精品久 |